Cell | Definition, Types, Functions, Diagram, Division, Theory,
2025年1月6日 · A cell, in biology, is the basic membrane-bound unit that contains the fundamental molecules of life and of which all living things are composed. A single cell may be …
Cell theory | Definition, History, Importance, Scientists, First ...
2025年1月14日 · Cell theory, fundamental scientific theory of biology according to which cells are held to be the basic units of all living tissues. First proposed by German scientists Theodor …
Biology | Definition, History, Concepts, Branches, & Facts | Britannica
2024年11月24日 · Cell biology is the study of cells—the fundamental units of structure and function in living organisms. Cells were first observed in the 17th century, when the compound …
Structure and types of cells | Britannica - Encyclopedia Britannica
cell, In biology, the basic unit of which all living things are composed; the smallest structural unit of living matter that is able to function independently. A single cell can be a complete organism in …
Cell - Molecules, Structure, Biology | Britannica
2025年1月6日 · Cell - Molecules, Structure, Biology: Cells are largely composed of compounds that contain carbon. The study of how carbon atoms interact with other atoms in molecular …
Stem cell | Definition, Types, Uses, Research, & Facts | Britannica
2025年1月16日 · A stem cell is an undifferentiated cell that can divide to produce some offspring cells that continue as stem cells and some cells that are destined to differentiate (become …
Membrane | Definition, Structure, & Functions | Britannica
membrane, in biology, the thin layer that forms the outer boundary of a living cell or of an internal cell compartment. The outer boundary is the plasma membrane, and the compartments …
Cell - Structure, Organelles, Metabolism | Britannica
2025年1月6日 · Cell - Structure, Organelles, Metabolism: Like the cell membrane, membranes of some organelles contain transport proteins, or permeases, that allow chemical communication …
Cell membrane | Definition, Function, & Structure | Britannica
2025年1月15日 · Cell membrane, thin membrane that surrounds every living cell. The cell membrane functions as a barrier, keeping cell constituents in and unwanted substances out, …
Biology - Cell Discovery, Microscopy, Histology | Britannica
2024年11月24日 · Biology - Cell Discovery, Microscopy, Histology: Of the five microscopists, Robert Hooke was perhaps the most intellectually preeminent. As curator of instruments at the …